Hiking up Mr Daisen is the major reason that people come to the Daisen area, but there are many other things that people can do there.
People can warm up with a nice footbath at Daisen Fire Onsen Footbath.
Their is a very nice Natural History Museum of Daisen where you can learn the history of the local area.
http://daisen-museum.jp/
One can walk the beautiful path and visit the ancient Daisen Temple which has a history that dates back over 1300 years.
http://daisenji.jp/